Springtime! Visions of tulips and daffodils and trees golden in new leaves. Eventually, yes, or at least we hope so, but in New Hampshire spring often brings with it a few reminders of winter. On this day, new snow lay heavy on the heather blossoms.
These blossoms are tiny -- certainly no bigger than a small kernel of corn. How to keep everything in focus? The "depth of field" -- the front-to-back distance of what's in focus -- was miniscule. An image like this relies on those many beautiful little details. What to do?
The answer is to use a nifty trick called focus stacking. The brief explanation is this: You take several photographs, each with a different aspect of the subject in focus, then let specialized software combine all of the in-focus areas into a single image. As the photograph above shows, the process is pretty much seamless and creates a realistic and honest image.
But wait! The eye sees the whole scene in focus. Why doesn't the camera? The short answer is that the eye seems to keep all the parts in focus, but the reality is that it shifts here and there, adjusting focus as it goes, and so creates the illusion of focus everywhere. In a sense, that's what focus stacking does as well.
On the day in question, I waited for the snowy breezes to die down, then took six or eight images, each focused on a different part of the scene. Photoshop then created the magic by combining the in-focus portions of each. And as a result, you see what I saw -- a twig carrying tiny little pink blossoms under a load of icy snow. Only in New Hampshire!